In a conventional rotating electrical machine having a cylindrical rotor, a slot axially passing through a rotor core is provided in plural numbers in the circumferential direction of the rotor core, a rotor winding that is a field winding is wound in a distributed winding manner and placed in each slot thereof, and a coil end portion of the rotor winding is arranged to be more projected than the core end face of the rotor core.
Furthermore, in the rotating electrical machine having the cylindrical rotor which is provided with a space by a narrow subslot and/or a U-shaped channel that supports the rotor winding on a slot bottom portion of each slot provided in the rotor core, refrigerant gas is ventilated in the space to cool the rotor winding.
In the conventional rotating electrical machine having the cylindrical rotor, the rotor having the subslot on the bottom portion of the slot of the rotor core improves cooling performance by arranging a streamlined body wedge block adjacent to the subslot. (For example, see Patent Document 1.)
Furthermore, in the rotor having the U-shaped channel on the bottom portion of the slot of the rotor core, a structure is made such that the projected end face of the U-shaped channel, which is more projected than the core end face of the rotor core, is axially projected than the projected end face of an adjacent interposed piece that is more projected than the core end face of the rotor core and the refrigerant gas becomes difficult to flow.
By the way, as the rotating electrical machine provided with the rotor having the U-shaped channel on the bottom portion of the slot of the rotor core, there is a configuration shown in, for example, FIG. 9 and FIG. 10. A rotor winding 3 is placed in a slot 2 of a rotor core 1 and a coil end portion of the rotor winding 3 is extended on the axially outer side than the core end face 1a of the rotor core 1. A U-shaped channel 4, which is touched to come into contact with a bottom portion of the rotor winding 3 and is axially extended, is arranged on a slot bottom portion 2a of the slot 2 of the rotor core 1; a projected end face 4a of the U-shaped channel 4 is projected on the axially outer side than the core end face 1a of the rotor core 1; and refrigerant gas is ventilated in the U-shaped channel 4 to cool the rotor winding 3.
A slot cell 5 is placed in the slot 2 of the rotor core 1; the rotor winding 3 and the U-shaped channel 4 in the slot 2 of the rotor core 1 are insulated from the rotor core 1 by the slot cell 5; the axial end face of the slot cell 5 is axially more projected than the core end face 1a of the rotor core 1 to insulate. In order to protect the slot cell 5, for example, the U-shaped channel 4 is projected on the axially outer side so that the projected end face 4a of the U-shaped channel 4 is the same as the projected end face of the slot cell 5.
An interposed piece 6 which is arranged between the rotor windings 3 at a portion more projected than the core end face 1a of the rotor core 1 is more projected than the core end face 1a of the rotor core 1 in a predetermined dimension, and is arranged to be extended in a straddle fashion over the rotor winding 3 and the U-shaped channel 4 to maintain each interval between the rotor windings 3 and between the U-shaped channels 4.
The projected end face 4a of the U-shaped channel 4 is arranged to be projected on the axially outer side by a value of P than the projected end face 6a of the interposed piece 6 in order to easily confirm a positional relationship after assembling peripheral components. Then, as shown by an arrow R1, the refrigerant gas is ventilated from the projected end face 4a side of the U-shaped channel 4 into the inside of the U-shaped channel 4 so as to cool the rotor winding 3.